1. Field of the Invention
Embodiments are directed to a reset control method and apparatus. More particularly, embodiments are directed to a reset control method and apparatus in a power management integrated circuit.
2. Description of the Related Art
Proper enablement of functional circuit blocks includes delaying operation of these blocks until the output of the power supply is stable. Ensuring proper enablement of functional circuit blocks on an integrated circuit (IC) is relatively simple when a regulated power supply is external to the IC. When a power converter is on the IC, however, proper enablement is more difficult to ensure, especially during power transition periods.
Power management circuits (PMCs) may be used to prevent functional circuit blocks from malfunctioning during an initial transition period, e.g., rising or falling period. In particular, during the transition period, the output voltage that the PMC is configured to control may be lower than a desired voltage. Functional circuit blocks that use the output voltage as a voltage source may malfunction due to the low voltage and/or a variation in voltage. To avoid these potential problems, the functional circuit blocks may be placed in a reset state during the transition period.
There are numerous advantages to using PMCs, including simpler dynamics, simpler robust output voltage control, and mitigation of transformer saturation problems. However, power supplied using PMCs may be more susceptible to noise than externally supplied power.